1 // a layer of 3d clouds
3 // Written by Harald JOHNSEN, started April 2005.
5 // Copyright (C) 2005 Harald JOHNSEN - hjohnsen@evc.net
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
24 # include <simgear_config.h>
27 #include <simgear/compiler.h>
31 #include <simgear/math/sg_random.h>
32 #include <simgear/math/sg_geodesy.hxx>
33 #include <simgear/math/polar3d.hxx>
35 #include STL_ALGORITHM
40 #include <simgear/environment/visual_enviro.hxx>
42 #include "newcloud.hxx"
43 #include "cloudfield.hxx"
45 #if defined(__MINGW32__)
46 #define isnan(x) _isnan(x)
49 #if defined (__FreeBSD__)
50 # if __FreeBSD_version < 500000
52 inline int isnan(double r) { return !(r <= 0 || r >= 0); }
58 #if defined (__CYGWIN__)
64 static list_of_culledCloud inViewClouds;
66 // visibility distance for clouds in meters
67 float SGCloudField::CloudVis = 25000.0f;
68 bool SGCloudField::enable3D = false;
69 // fieldSize must be > CloudVis or we can destroy the impostor cache
70 // a cloud must only be seen once or the impostor will be generated for each of his positions
71 double SGCloudField::fieldSize = 50000.0;
72 float SGCloudField::density = 100.0;
73 double SGCloudField::timer_dt = 0.0;
74 sgVec3 SGCloudField::view_vec, SGCloudField::view_X, SGCloudField::view_Y;
76 static int last_cache_size = 1*1024;
77 static int cacheResolution = 64;
78 static sgVec3 last_sunlight={0.0f, 0.0f, 0.0f};
80 int SGCloudField::get_CacheResolution(void) {
82 return cacheResolution;
87 void SGCloudField::set_CacheResolution(int resolutionPixels) {
89 if(cacheResolution == resolutionPixels)
91 cacheResolution = resolutionPixels;
93 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
96 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
101 int SGCloudField::get_CacheSize(void) {
103 return SGNewCloud::cldCache->queryCacheSize();
108 void SGCloudField::set_CacheSize(int sizeKb) {
110 // apply in rendering option dialog
111 if(last_cache_size == sizeKb)
116 last_cache_size = sizeKb;
118 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
121 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
125 void SGCloudField::set_CloudVis(float distance) {
127 if( distance <= fieldSize )
128 SGCloudField::CloudVis = distance;
131 void SGCloudField::set_density(float density) {
133 SGCloudField::density = density;
136 void SGCloudField::set_enable3dClouds(bool enable) {
138 if(enable3D == enable)
142 int count = last_cache_size * 1024 / (cacheResolution * cacheResolution * 4);
145 SGNewCloud::cldCache->setCacheSize(count, cacheResolution);
147 SGNewCloud::cldCache->setCacheSize(0);
152 // reposition the cloud layer at the specified origin and orientation
153 void SGCloudField::reposition( sgVec3 p, sgVec3 up, double lon, double lat, double alt, double dt, float direction, float speed) {
158 sgMakeTransMat4( T1, p );
160 sgSetVec3( axis, 0.0, 0.0, 1.0 );
161 sgMakeRotMat4( LON, lon * SGD_RADIANS_TO_DEGREES, axis );
163 sgSetVec3( axis, 0.0, 1.0, 0.0 );
164 sgMakeRotMat4( LAT, 90.0 - lat * SGD_RADIANS_TO_DEGREES, axis );
168 sgCopyMat4( TRANSFORM, T1 );
169 sgPreMultMat4( TRANSFORM, LON );
170 sgPreMultMat4( TRANSFORM, LAT );
173 sgSetCoord( &layerpos, TRANSFORM );
175 sgMakeCoordMat4( transform, &layerpos );
180 // simulate clouds movement from wind
181 double sp_dist = speed*dt;
183 double bx = cos((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
184 double by = sin((180.0-direction) * SGD_DEGREES_TO_RADIANS) * sp_dist;
185 relative_position[SG_X] += bx;
186 relative_position[SG_Y] += by;
189 if ( lon != last_lon || lat != last_lat || sp_dist != 0 ) {
190 Point3D start( last_lon, last_lat, 0.0 );
191 Point3D dest( lon, lat, 0.0 );
192 double course = 0.0, dist = 0.0;
194 calc_gc_course_dist( dest, start, &course, &dist );
195 // if start and dest are too close together,
196 // calc_gc_course_dist() can return a course of "nan". If
197 // this happens, lets just use the last known good course.
198 // This is a hack, and it would probably be better to make
199 // calc_gc_course_dist() more robust.
200 if ( isnan(course) ) {
201 course = last_course;
203 last_course = course;
206 // calculate cloud movement due to external forces
207 double ax = 0.0, ay = 0.0;
210 ax = cos(course) * dist;
211 ay = sin(course) * dist;
222 // correct the frustum with the right far plane
223 ssgContext *context = ssgGetCurrentContext();
224 frustum = *context->getFrustum();
227 sgEnviro.getFOV( w, h );
228 frustum.setFOV( w, h );
229 frustum.setNearFar(1.0, CloudVis);
234 SGCloudField::SGCloudField() :
242 sgSetVec3( relative_position, 0,0,0);
243 theField.reserve(200);
244 inViewClouds.reserve(200);
245 sg_srandom_time_10();
251 SGCloudField::~SGCloudField() {
253 list_of_Cloud::iterator iCloud;
254 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
255 delete iCloud->aCloud;
262 void SGCloudField::clear(void) {
264 list_of_Cloud::iterator iCloud;
265 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
266 delete iCloud->aCloud;
269 // force a recompute of density on first redraw
271 // true to come back in set density after layer is built
276 // use a table or else we see poping when moving the slider...
277 static int densTable[][10] = {
278 {0,0,0,0,0,0,0,0,0,0},
279 {1,0,0,0,0,0,0,0,0,0},
280 {1,0,0,0,1,0,0,0,0,0},
281 {1,0,0,0,1,0,0,1,0,0}, // 30%
282 {1,0,1,0,1,0,0,1,0,0},
283 {1,0,1,0,1,0,1,1,0,0}, // 50%
284 {1,0,1,0,1,0,1,1,0,1},
285 {1,0,1,1,1,0,1,1,0,1}, // 70%
286 {1,1,1,1,1,0,1,1,0,1},
287 {1,1,1,1,1,0,1,1,1,1}, // 90%
288 {1,1,1,1,1,1,1,1,1,1}
291 // set the visible flag depending on density
292 void SGCloudField::applyDensity(void) {
294 int row = (int) (density / 10.0);
298 list_of_Cloud::iterator iCloud;
299 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
302 if( densTable[row][col] ) {
303 iCloud->visible = true;
304 fieldBox.extend( *iCloud->aCloud->getCenter() );
306 iCloud->visible = false;
308 last_density = density;
309 draw_in_3d = ( theField.size() != 0);
311 sgSubVec3( center, fieldBox.getMax(), fieldBox.getMin() );
312 sgScaleVec3( center, 0.5f );
314 field_sphere.setCenter( center );
315 field_sphere.setRadius( fieldSize * 0.5f * 1.414f );
319 // add one cloud, data is not copied, ownership given
320 void SGCloudField::addCloud( sgVec3 pos, SGNewCloud *cloud) {
325 cloud->SetPos( pos );
326 sgCopyVec3( cl.pos, *cloud->getCenter() );
327 theField.push_back( cl );
332 static float Rnd(float n) {
333 return n * (-0.5f + sg_random());
337 // build a field of cloud of size 25x25 km, its a grid of 11x11 clouds
338 void SGCloudField::buildTestLayer(void) {
340 const float s = 2250.0f;
342 for( int z = -5 ; z <= 5 ; z++) {
343 for( int x = -5 ; x <= 5 ; x++ ) {
344 SGNewCloud *cloud = new SGNewCloud(SGNewCloud::CLFamilly_cu);
346 sgVec3 pos = {(x+Rnd(0.7)) * s, 750.0f, (z+Rnd(0.7)) * s};
347 addCloud(pos, cloud);
354 // cull all clouds of a tiled field
355 void SGCloudField::cullClouds(sgVec3 eyePos, sgMat4 mat) {
357 list_of_Cloud::iterator iCloud;
359 sgSphere tile_sphere;
360 tile_sphere.setRadius( field_sphere.getRadius() );
362 sgSubVec3( tile_center, field_sphere.getCenter(), eyePos );
363 tile_sphere.setCenter( tile_center );
364 tile_sphere.orthoXform(mat);
365 if( frustum.contains( & tile_sphere ) == SG_OUTSIDE )
368 for( iCloud = theField.begin() ; iCloud != theField.end() ; iCloud++ ) {
371 if( ! iCloud->visible )
373 sgSubVec3( dist, iCloud->pos, eyePos );
374 sphere.setCenter(dist[0], dist[2], dist[1] + eyePos[1]);
375 float radius = iCloud->aCloud->getRadius();
376 sphere.setRadius(radius);
377 sphere.orthoXform(mat);
378 if( frustum.contains( & sphere ) != SG_OUTSIDE ) {
379 float squareDist = dist[0]*dist[0] + dist[1]*dist[1] + dist[2]*dist[2];
381 tmp.aCloud = iCloud->aCloud;
382 sgCopyVec3( tmp.eyePos, eyePos );
383 // save distance for later sort, opposite distance because we want back to front
384 tmp.dist = - squareDist;
385 tmp.heading = -SG_PI/2.0 - atan2( dist[0], dist[2] ); // + SG_PI;
386 tmp.alt = iCloud->pos[1];
387 inViewClouds.push_back(tmp);
388 if( squareDist - radius*radius < 100*100 )
389 sgEnviro.set_view_in_cloud(true);
396 // Render a cloud field
397 // because no field can have an infinite size (and we don't want to reach his border)
398 // we draw this field and adjacent fields.
399 // adjacent fields are not real, its the same field displaced by some offset
400 void SGCloudField::Render(void) {
408 if( last_density != density ) {
409 last_density = density;
416 if( ! SGNewCloud::cldCache->isRttAvailable() )
419 inViewClouds.clear();
424 sgMat4 modelview, tmp, invtrans;
426 // try to find the sun position
427 sgTransposeNegateMat4( invtrans, transform );
429 ssgGetLight( 0 )->getPosition( lightVec );
430 sgXformVec3( lightVec, invtrans );
432 sgSetVec3( SGNewCloud::modelSunDir, lightVec[0], lightVec[2], lightVec[1]);
433 // try to find the lighting data (not accurate)
434 sgVec4 diffuse, ambient;
435 ssgGetLight( 0 )->getColour( GL_DIFFUSE, diffuse );
436 ssgGetLight( 0 )->getColour( GL_AMBIENT, ambient );
437 // sgScaleVec3 ( SGNewCloud::sunlight, diffuse , 1.0f);
438 sgScaleVec3 ( SGNewCloud::ambLight, ambient , 1.1f);
439 // trying something else : clouds are more yellow/red at dawn/dusk
440 // and added a bit of blue ambient
441 float *sun_color = thesky->get_sun_color();
442 sgScaleVec3 ( SGNewCloud::sunlight, sun_color , 0.4f);
443 SGNewCloud::ambLight[2] += 0.1f;
446 sgSubVec3(delta_light, last_sunlight, SGNewCloud::sunlight);
447 if( (fabs(delta_light[0]) + fabs(delta_light[1]) + fabs(delta_light[2])) > 0.05f ) {
448 sgCopyVec3( last_sunlight, SGNewCloud::sunlight );
449 // force the redraw of all the impostors
450 SGNewCloud::cldCache->invalidateCache();
453 // voodoo things on the matrix stack
454 ssgGetModelviewMatrix( modelview );
455 sgCopyMat4( tmp, transform );
456 sgPostMultMat4( tmp, modelview );
458 // cloud fields are tiled on the flat earth
459 // compute the position in the tile
460 relx = fmod( deltax + relative_position[SG_X], fieldSize );
461 rely = fmod( deltay + relative_position[SG_Y], fieldSize );
463 relx = fmod( relx + fieldSize, fieldSize );
464 rely = fmod( rely + fieldSize, fieldSize );
465 sgSetVec3( eyePos, relx, alt, rely);
467 sgSetVec3( view_X, tmp[0][0], tmp[1][0], tmp[2][0] );
468 sgSetVec3( view_Y, tmp[0][1], tmp[1][1], tmp[2][1] );
469 sgSetVec3( view_vec, tmp[0][2], tmp[1][2], tmp[2][2] );
471 ssgLoadModelviewMatrix( tmp );
486 for(int x = -1 ; x <= 1 ; x++)
487 for(int y = -1 ; y <= 1 ; y++ ) {
489 // pretend we are not where we are
490 sgSetVec3(fieldPos, eyePos[0] + x*fieldSize, eyePos[1], eyePos[2] + y*fieldSize);
491 cullClouds(fieldPos, tmp);
493 // sort all visible clouds back to front (because of transparency)
494 std::sort( inViewClouds.begin(), inViewClouds.end() );
497 glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
498 glEnable(GL_ALPHA_TEST);
499 glAlphaFunc(GL_GREATER, 0.0f);
500 glDisable(GL_CULL_FACE);
501 glEnable(GL_DEPTH_TEST);
502 glDepthMask( GL_FALSE );
505 glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA );
506 glEnable( GL_TEXTURE_2D );
508 glDisable(GL_LIGHTING);
510 // test data: field = 11x11 cloud, 9 fields
511 // depending on position and view direction, perhaps 40 to 60 clouds not culled
512 list_of_culledCloud::iterator iCloud;
513 for( iCloud = inViewClouds.begin() ; iCloud != inViewClouds.end() ; iCloud++ ) {
514 // iCloud->aCloud->drawContainers();
515 iCloud->aCloud->Render(iCloud->eyePos);
516 sgEnviro.callback_cloud(iCloud->heading, iCloud->alt,
517 iCloud->aCloud->getRadius(), iCloud->aCloud->getFamilly(), - iCloud->dist, iCloud->aCloud->getId());
520 glBindTexture(GL_TEXTURE_2D, 0);
521 glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
523 glEnable(GL_CULL_FACE);
524 glEnable(GL_DEPTH_TEST);
526 ssgLoadModelviewMatrix( modelview );